Optical system



A ofvite 'actuated b l framed .Mie-1. 192s..

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l This invention lrelates,toot-)tical systems,V and more particularly to optical, .systems adapted for use `in the 'transmission of views by electricity. l 5 The object 'ofthe invention is un improved method of scanning on object, screen,

receiving surfaceor the like.

A feature of the invention relates toen optical system in which en object maj,` be 30 explored by the use of mirrors arranged to vibrate about parallel axes.

Another Yfeature, relates -to a syste'n in which zi riglit-angle prism is employed to rotate the image of an object through a right angle to enable an aree' to be scanned 'by4 two mirrors each-having a single viy bratory motion :rnd the axes of vibra-tion bcing parallel. f

Other features and nd'nntges of the in- 90 vention will appear irom the following-,de-

tailed description and the appended claims. In the drawing. Figure 1 illustrates on optical system embodying the features of this invention. Fig'. 2 is an enlarged View of the .prism used in the system.

' Fig. 3 discloses a modification of the system'.

- Fig. 4 is a ,detailed showing of the mirrors employed in the system ofy Fig. 3.

In order to 'gire'V an explicit ldescription of the invention, it has been shown as cmbodied in nn'opticnlsystem surh :rs found 'at the sending vsint-ion of a picture tr-nnsmission or television system. The system consists primarily of a source of light- 1. e nir ot reflecting;r devices such ns-mirrf x- 3 and 10,' n prism 8, a lens 30nnd .ar photoelectrie cell 15. The lens 30 is provided between the mirrors and the'cell 15 to form Athe image oftheiobject in the plane of an aperture 31 in front of the cell.

The mirror-'3 is mounted on nn deter. .ined by the pivots 4 and 5 for a simple single''vibrutory motion about said axis. To

i impart this movement to themirro r, there is provided a driving member which may be attached to :my suitable-niecbnnism such as the armature of an electromagnetic de- Y alternating or other Tari- 'able current. The 'second mirror 10 is mounted' upon an axis determined by the pivots 11 and 12 which is parallel to the gr'xissterm- Y p ,p

1, 192s. swarm. 72,5351

of the first mirror end is therefore vibratedv in the s'frme direction as the mirror 3. driving lmember 13 is also provided for os# cillating the mirror 10 about its axis;

A prism 8 is situated at some suitable point which is opticallyv intermediate ofthe mirrors 3 and 10. The prism 8 is preferably' im isosccles right angle prism and mav be of quartz to secure .greater sensitivity ofthe photoeleetric cell. It is properly located in 'the opt-ical system by first pl such a position that a right triangle section abc is perpendicular to the lane eontaining the mies of mirrors 3 an 10, and then rotating the -prs'm about the 4hypotenuse be until the plane containing the right angle section abcintersects vlthe axes of the mirrors at an' single of `fort five degrees. The tilted "position of tlie prism 8 is better-'seen from Fig. 2.'

In order to vsecure .greater sensitivity, the

If 'it is desired to transmit 4en image of an object 2 to n distunce, the object is introduced into, ,tli e',flptjgrij3i sition that its -reflecied'liglitpa'sses' to the mirror 3. It will also be apparent that if the object 2 is in the form of a transparent. film, the some result may be had by causing light from the source 1 to shinethrough the' objet-t2 onto the surface ofthe mirror. The light thus reaching the mirror 3 'is rg-v fief-tedl thereby und enters the side .a'bde of prismB. The light. passes tothe side bcfd where it is reflected and then emcrgespfrom the side acfe und passes to the surface of the second 'mirror' 10; The mirror 10 reflects .the light received to the lens 30 which forms nn inmgev of 'the original obj-ect in the plane ofthe aperture 31 und into the cell 1,5.

The operation of the system shown 'in Fig. 1 will .now he briefly described. .A ssume tlrit the object 2' is placed in the poy silio'n shmvnrelative. to the mirror 3; inf other words. the object horizontally ar ranged with'rcspect to its greater dimension. By 'vilirutirrlv the mirror 3 about its axis 45. a beam of li shown by the brolen lines will vbe 'caused to ritira-te. hack and forth ina horizontalplane.A

The ligure T, which may represent en image of the obgect 2, :is seenjby an observer m AviV` :icing it 'in' the plane conminingm eht traveling the pa.th

vthe mirror 3, has the same verticaland horiof the prism.

zontal disposition as theohiect itself. In effect, the mirror 3 causes light from the object reflected from the mirrorwto vibrate back vand forth horizontally across. the sux"- face of the prism 8.

The light representing the object 2 is ne? lected by the mirror 3 and enters vthe. side abde of the ris'm 8.- This light in assin to the side d) due to the angle at which the prism .is indined. Thefignr'e 9 represents the .direction of vibration of the beam of light in the prism 8, rotation through an angle of forty,- five degrees' from the horizontal havin taken place. Light from the surface d c is reflected and emerges from the side acfe During this .passage to the emerging side, it is again refracted so that the axis of the figure 9 is rotated through v'to cause'the beams of light to scan theol)-i another angle offfo'rtyive degree-s inv the samedirecti'On.. Thus, the ligure 14 shown on the mirrorl represents an image of the` object, 2 which appearsto an observer-to have been rotatedthrough a complete angle of lninety degrees from the position of. the object 2' due to the refraction of the prism 8. Since the mirror 10 is oscillated in the saine direction as the mirror 3, the eect is ject 2 in a direction at right angles to the direction of .scanning by the mirror 3. Then nai'rrorllO reflects the light to the lens 30 which forrns an image in the plate of aper-` ture 31. The lightwhich passes through enters the cell and causes, 4in the well linearenv manner. the liberation of photoelectrons to establish in the circuit 22 a carre-nt vwhich is directly proportional to theltone values of the .elemental areas of the ohject z2' being scanned.- The elementary areas of the .image are passed in succession infront of the ap erture 31 due to the xnethod'of scanning,

From the foregoing descriptiomit Will'be A' seen 'that if a single beam of lightv is consid'ered as reaching the plzotoelec'tric ce-ll lobject; Eby. the mirror 10. In vother words,

' the image formedin the' plane of the aperture 31 is thus caused` to -rnove vertically. backend forth by' means: of .mirror 3 andv prism 8 and horizontally by means-:cf mirror 10, so that .all elements of'said iin-aga pass over the aperture. If Athe mirrors 3 V and 10 are driven at suitable relative speeds of oscillation, the effect. ifs-the scanning of the entire area of the object 2.

Fig. l shows morexclearljc the mamxe'in which the light from the object, 2 is rotated hy refraction til-rough an angle of ninety about degrees. The arrow 24 indicates the direc'- ti'o'n of entrance o the lighgjand the arrow 25 thefdirection or' emergence.

Fig. 3 illustrates a. modificationin which ror 18 for oscillationl by the drir'irig memdic of the prisni is rie ractc ,'fbr 19- Tli lf-m 0f, lghtpassing from the source 1 .is -retlected from the surface of the object 2 to the' surface of mirror i6.` 'It is nlv .lation by a driving member 17,-and the rn'ir-l Y* prism 8, from which it emerges and passes tothe surface of a stationary mirror 20. The mirror 2O renects the beam to the surface ofa second vibrating mirror 1S adjacent to. mirrorl as shown in Fig. 4, from which it is 'reflected to lens 30 which. forms an image of the object -in the plane of the apcrtnre 31 near the photoelectric cell 15.

While the invention has been shown in specific embodiments, 'it will be obvious that various arrangements may .be employed as desired. For example, the prism may be rotated throgh some ang-le other than fortyfive degrees to determine the amount of rotation ofl the image desired. Also, the mirrors may be poljrhedral andl arranged for continuous rotation. The relative speeds of the twofmirrors' may lDe regulated to gire suchpatt'erns ,of .scanning as may be desirable. j A

TVl'iile the opticalsys'tem has been shown as applied to the transmission station" ofi-a picture transmision or television system, it. the 'receiving mayalso be 'adapted tense at station.

A picture `transiznission sy cable is illustrated in the la pplieat-ion of Hor- 1.l The combination in of an object to he scanned, inea-ns 'including an optical sistem lem of the gen-v eral type towhieh this invention is appliasource of light for prodncingan image of.

said object, a plnrali-tyjof mirrors errang for vibration on parallel axes, Aand means cooperating with said mirrors for moving said image in a plnrality of directions 2. The r-zomhination in anoptical System of an object to be'scanned, means includ-ing' l a' scarce of light for'pro'd-acing an image of said object', a plurality of' mirrors each :1rranged-for a single vihrato'ry motion about' parallel axes, a member Aliatfing an 'r1-perfil@ and. means cooperating A`with said mirrors for Apresenting' successive elem'en talV 'portions othe image to sai-d apertiire.`

8,. The combination .in anoptigcal system etai object to bescannefL-maans including a. sonrceof iightv for oriningigan infrage ofsaldcbje'ct, a plurality of mirrors arranged with theirl surfaces' parallel. for wfibratin-g parallel and coasting with amA im i

l said mirrorsfor' causing saidirnage to more in Va lurality of directions.v

4. iilfhe combinations in an opi-ical system of an objectto be explored, .means compris.- ing a source of light for forming an image of said object, a plurality of mirrors arranged for vibration" on parallel means cooperating with said mirrors where said mirrors respectively im art. to the imagecomponents of motion in i'ferent di' rections.' i

5. In an opal system, an object, a source' of light for illuminating Said objeot, avi 'oratory mirror for vibrating n beam of light; i' rom said-souroe ina given plane, means for rotating the plane of vibration through an angle whereby' the vibration of the beam' is in a plane at'an angie to the -first mentioned plane, and a second mirror vibrating in the same direction as the iirst mirror for giving, said'beam a second vibratory movement in Aille rst mentioned plane. l

6.' 1n an optical sycexn, an object, means inlndi-ng a source o light for forming image of said object, a plurality of mirrors arranged for vibration yon parallel axes, and a prisxmoooperating with" said mirrors for cnnsngead image to' Amore in a plurality 'of 'drectionj 7. In an optieal system,- an objectto explored, means incldingn source of light; l

Leones? Aglecl prim having' the plano of a rig-t tri-- axes, and

'tion on parallel axes,

of :in object to bescanned, meansincludin ",eniting with ille mirrors for for forming an image-oi ebjecf'-, two 'mi-L v rcrs -for reiecting said ,light arranged for vibration on parallel axes., vand a ri 'intra-n angular section ivx'iclfined at an .angle taoiiie lane o-f said mirrors 'for .roatin 'said'- lma e of hev object tnrou-gh-an -anjg e pro portionnl lo theangle of inclination.

8.11m an optical s Stern, an 'obje-ct to be explored', a source o? light for irllaminating -the object, 'two mirrorsari-.anged for 'vibra-l and a right-angied prism having the plagne-of a :light triangular sect-ion i1nclined'- at an angle of fortyA-ve deV grecs to the plane of said mirrors for rotating an image 'of ,the objet through-1n angle o ninety degrees .to the angle of inclina; om I l ,9. The combination" in an optical system 'aV source of light :for -ormingan image o said object,- a pair of 'vibratory mirrors having parallel-aimee, means for 4driving mirrors :lt-'different speeds, and means coepf' -eausing the" image to 'move in two different dir'ot'ons;

In teetimony'vhereo, I have signed my' name to ibis Specification- Novembe'r, 1925. i

this 30th day of 'I FREERIGKWQYNQLDS if 

